Begin by preheating your oven to 350°F (175°C). Prepare a muffin tin by placing paper liners in each cup or greasing them lightly.

If desired, toast the chopped pecans in a dry skillet over medium heat for about 3-4 minutes until they become fragrant.

In a large mixing bowl, whisk together the all-purpose flour, brown sugar, baking powder, baking soda, and salt until fully blended.

In a separate bowl, whisk the large eggs until they are light and frothy. Add in the melted butter, milk or buttermilk, and vanilla extract, mixing until well combined.

Pour the wet ingredients into the bowl of dry ingredients, stirring gently until just combined. Gently fold in most of the toasted pecans.

Using a scoop or spoon, fill each prepared muffin cup about 3/4 full with the batter. Top each muffin with the reserved pecans.

Place the muffin tin in the preheated oven and bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, remove the muffins from the oven and allow them to cool in the pan for about 5 minutes before transferring to a wire rack.